Gravity Powered Aircraft ???

[stuartcox]

Is this the technology of the future?
I would never like to be in a fuelless, gravity powered plane. The only way is...down!

http://www.youtube.com/watch?v=tPbu5UeW4uk

[Skittles]

I think they're called gliders.

[tigisfat]

Is this the technology of the future?
I would never like to be in a fuelless, gravity powered plane. The only way is...down!

http://www.youtube.com/watch?v=tPbu5UeW4uk


There've been rumors of gravity repelling propulsion for some time. Nothing surprises me, but I'm not sure how something would run on time/gravity. That's a bit like saying something could run downhill all the time. If anything, I could imagine it like a sailboat. Something running on gravity would be hardpressed to move in exact points through space.

Clearly, it's over my head. I'm just speculating.

[stuartcox]

And certainly mine!

[aeromed202]

Aren't they all when the gas runs out?

[MaddogK]

I think they're called gliders.

Technically I think they're called bricks.

Would this fall into the 'perpetual motion machine' catagory ?

[Lionheart]

I had seen this last year. Many people have been playing with dirigibles shaped like planes so they could glide. In this case, the blimp uses lift to move forward, opposite of a glider descent.

Helium is so wierd. If you have a tank of it and decompress it, its lighter then air. But if you compress it into a tank, it cant take-off.... Go figure...

Negative buoyancy blimps are amazing. They need forward motion to fly. Turn off the power and they gently return home..



Bill

[tigisfat]

There've been rumors of gravity repelling propulsion for some time. Nothing surprises me, but I'm not sure how something would run on time/gravity. That's a bit like saying something could run downhill all the time. If anything, I could imagine it like a sailboat. Something running on gravity would be hardpressed to move in exact points through space.

Clearly, it's over my head. I'm just speculating.

I actually just watched the video.I thought they were talking about gravity propulsion, not a glider.

How could passengers be comfortable in something that screams along like it's doing parabolic arcs over and over? What speed is this thing's L/D max?

[aeromed202]

I think this thing could more correctly be called density driven? As for all the propulsion phases, I don't know. Sounds way too complex for what a blimp does now with an engine. And to get a sleek enough frame for speed, yet enough cubic space for balloon-like buoyancy? Still, it's putting out concepts this way that have bourne fruit before. Ok I'm over-doing this.


Wait Bill. Negative buoyancy blimp? If a buoyant blimp goes up, do these just go down? I'm looking it up now.

[Cratermaker]

Interesting idea, but I see one big flaw in their presentation. It's the part where they say they would have a 400-600 mile range per gravity descent. They also say that power is stored from turbines during the descent which will power the compressors. Though they don't actually say it, they imply that the process can be repeated indefinitely. That would be a perpetual motion machine. Some energy has to be added from somewhere else or each cycle will be less useful than the previous one.

[tigisfat]

Interesting idea, but I see one big flaw in their presentation. It's the part where they say they would have a 400-600 mile range per gravity descent. They also say that power is stored from turbines during the descent which will power the compressors. Though they don't actually say it, they imply that the process can be repeated indefinitely. That would be a perpetual motion machine. Some energy has to be added from somewhere else or each cycle will be less useful than the previous one.


I also don't see how they're going to provide power to all the computers, life support systems, hydraulics whatever else. If they plan on doing this with turbines, then cratermaker's point becomes all the more important.

I'd sure like to see how far compressed air tanks that small will drive that thing, and the thrust it develops. It sure plans on storing a lot of helium and compressed air.

[Ken Stallings]

I think they're called gliders.

Kid you not, that was my immediate reaction when I saw the thread title! LOL!!!

But really a glider is thermal powered and gravity balanced. :engel016:

Cheers,

Ken

[Ken Stallings]

Actually, duh, I just remembered we have true gravity powered aircraft. The space shuttle in orbit is truly gravity powered.

Cheers,

Ken

[Lionheart]

Wait Bill. Negative buoyancy blimp? If a buoyant blimp goes up, do these just go down? I'm looking it up now.

Yep.. Usually its a lifting body type of shape with fins and engine powered fans keep it up. Sometimes they are very very light, where if you get out of the thing, it will rise.

The one in the video is definately a blimp that is an airliner.. I guess its technically a dirigible.

The beauty of Negative Bouyancy blimps is that they come back to Earth in a catastrophic failure, where as a true blimp could accidentally go to high atmosphere and if you have no oxygen, its over for the passengers.

Its derived from the new sport submarines that are positive bouyancy, (opposite), where if the sub craft loses power, etc, (catastrophic failure), the craft returns to the surface instead of sinking.. What it does is 'flies downward' using thrust and fins for downward flight.

Bill